台湾海峡中北部海域春季小型底栖生物丰度和生物量

Abundance and biomass of meiobenthos in central and northern Taiwan Strait during spring

2009年4月14～16日在台湾海峡中北部海域进行了小型底栖生物调查研究.结果表明,研究海域的小型底栖生物平均丰度为21.11±16.29 ind/cm2;平均生物量为20.97±4.96μg/cm2(以干重记).研究海域共鉴定出13个小型底栖生物类群,按丰度,最优势类群为自由生活海洋线虫其丰度为19.23±15.49 ind/cm2,占小型底栖生物总丰度的91.10%,其他优势类群依次为底栖桡足类和多毛类,分别占小型底栖生物总丰度的2.77%和2.64%;分布在0～5 cm的表层沉积物内的小型底栖生物约为83.18%,线虫和底栖桡足类分布在0～2 cm的比例分别为57.66%和62.96%.小型底栖生物的生物量低于大型底栖生物,但由于其繁殖快,生命周期短,因此,其生物量约为大型底栖生物的445倍,年平均生产量约为大型底栖生物的1.39倍.

The meiobenthos abundance and biomass in the central and northern Taiwan Strait was evaluated based on samples collected during April,2009.The results revealed that the meiobenthos average abundance and biomass was 21.11±16.29 ind/cm^2 and 20.97±4.96 g/cm^2（dry weight）,respectively.A total of 13 meiobenthos groups were indentified.Nematodes were present in the greatest abundance（19.23±15.49 ind/cm^2）,accounting for 91.10% of the total meiobenthos abundance.This was followed by benthic copepods（2.77%） and polychaetes（2.64%）.Analysis of the vertical distribution of meiobenthos indicated that 83.18% of the meiobenthos were distributed in the top 5 cm of sediment.Approximately 57.66% of nematodes and 62.96% of copepods were distributed in the top 2 cm of sediment.Comparison of the abundance,biomass and production of meiobenthos with macrobenthos indicated that the meiobenthos biomass is lower,but because of the rapid growth and much shorter life cycles of the meiobenthos,its abundance was about 445 times higher than that of macrobenthos.Additionally,the average production of meiobenthos is about 1.39 times greater that of macrobenthos.However,more information is needed to identify the importance of these small animals in the energy flow of the benthic ecosystem in the Taiwan Strait.